Fix spanning cell painting background from wrong row

third_party/WebKit/Source/core/layout/LayoutTableSectionTest.cpp

Index: third_party/WebKit/Source/core/layout/LayoutTableSectionTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableSectionTest.cpp b/third_party/WebKit/Source/core/layout/LayoutTableSectionTest.cpp
index 30cda09ad0218ada1553cdb88fa544e2b149c1c0..3a83caba8a64a4b4256e349481eaceabb70af5a5 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSectionTest.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSectionTest.cpp
@@ -4,6 +4,7 @@
 
 #include "core/layout/LayoutTableSection.h"
 
+#include "core/layout/LayoutTableCell.h"
 #include "core/layout/LayoutTestHelper.h"
 
 namespace blink {
@@ -16,8 +17,8 @@ TEST_F(LayoutTableSectionTest,
        BackgroundIsKnownToBeOpaqueWithLayerAndCollapsedBorder) {
   setBodyInnerHTML(
       "<table style='border-collapse: collapse'>"
-      "  <thead id='section' style='will-change: transform; background-color: "
-      "blue'>"
+      "  <thead id='section' style='will-change: transform;"
+      "       background-color: blue'>"
       "    <tr><td>Cell</td></tr>"
       "  </thead>"
       "</table>");
@@ -91,6 +92,125 @@ TEST_F(LayoutTableSectionTest, EmptySectionDirtiedEffectiveColumns) {
   EXPECT_EQ(1u, cellSpan.end());
 }
 
+TEST_F(LayoutTableSectionTest, PrimaryCellAtAndOriginatingCellAt) {
+  setBodyInnerHTML(
+      "<table>"
+      "  <tbody id='section'>"
+      "    <tr>"
+      "      <td id='cell00'></td>"
+      "      <td id='cell01' rowspan='2'></td>"
+      "    </tr>"
+      "    <tr>"
+      "      <td id='cell10' colspan='2'></td>"
+      "    </tr>"
+      "  </tbody>"
+      "</table>");
+
+  // x,yO: A cell originates from this grid slot.
+  // x,yS: A cell originating from x,y spans into this slot.
+  //       0         1
+  // 0   0,0(O)    0,1(O)
+  // 1   1,0(O)    1,0/0,1(S)
+  auto* section = toLayoutTableSection(getLayoutObjectByElementId("section"));
+  auto* cell00 = getLayoutObjectByElementId("cell00");
+  auto* cell01 = getLayoutObjectByElementId("cell01");
+  auto* cell10 = getLayoutObjectByElementId("cell10");
+
+  EXPECT_EQ(cell00, section->primaryCellAt(0, 0));
+  EXPECT_EQ(cell01, section->primaryCellAt(0, 1));
+  EXPECT_EQ(cell10, section->primaryCellAt(1, 0));
+  EXPECT_EQ(cell10, section->primaryCellAt(1, 1));
+  EXPECT_EQ(cell00, section->originatingCellAt(0, 0));
+  EXPECT_EQ(cell01, section->originatingCellAt(0, 1));
+  EXPECT_EQ(cell10, section->originatingCellAt(1, 0));
+  EXPECT_EQ(nullptr, section->originatingCellAt(1, 1));
+}
+
+TEST_F(LayoutTableSectionTest, DirtiedRowsAndDirtiedEffectiveColumnsWithSpans) {
+  setBodyInnerHTML(
+      "<style>"
+      "  td { width: 100px; height: 100px; padding: 0 }"
+      "  table { border-spacing: 0 }"
+      "</style>"
+      "<table>"
+      "  <tbody id='section'>"
+      "    <tr>"
+      "      <td></td>"
+      "      <td rowspan='2'></td>"
+      "      <td rowspan='2'></td>"
+      "    </tr>"
+      "    <tr>"
+      "      <td colspan='2'></td>"
+      "    </tr>"
+      "    <tr>"
+      "      <td colspan='3'></td>"
+      "    </tr>"
+      "  </tbody>"
+      "</table>");
+
+  // x,yO: A cell originates from this grid slot.
+  // x,yS: A cell originating from x,y spans into this slot.
+  //      0          1           2
+  // 0  0,0(O)    0,1(O)      0,2(O)
+  // 1  1,0(O)    1,0/0,1(S)  0,2(S)
+  // 2  2,0(O)    2,0(S)      2,0(S)
+  auto* section = toLayoutTableSection(getLayoutObjectByElementId("section"));
+
+  // Cell 0,0 only.
+  auto span = section->dirtiedRows(LayoutRect(5, 5, 90, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(1u, span.end());
+  span = section->dirtiedEffectiveColumns(LayoutRect(5, 5, 90, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(1u, span.end());
+
+  // Rect intersects the first row and all originating primary cells.
+  span = section->dirtiedRows(LayoutRect(5, 5, 290, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(1u, span.end());
+  span = section->dirtiedEffectiveColumns(LayoutRect(5, 5, 290, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(3u, span.end());
+
+  // Rect intersects (1,2). Dirtied rows also cover the first row to cover the
+  // primary cell's originating slot.
+  span = section->dirtiedRows(LayoutRect(205, 105, 90, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(2u, span.end());
+  span = section->dirtiedEffectiveColumns(LayoutRect(205, 105, 90, 90));
+  EXPECT_EQ(2u, span.start());
+  EXPECT_EQ(3u, span.end());
+
+  // Rect intersects (1,1) which has multiple levels of cells (originating from
+  // (1,0) and (0,1), in which (1,0) is the primary cell).
+  // Dirtied columns also cover the first column to cover the primary cell's
+  // originating grid slot.
+  span = section->dirtiedRows(LayoutRect(105, 105, 90, 90));
+  EXPECT_EQ(1u, span.start());
+  EXPECT_EQ(2u, span.end());
+  span = section->dirtiedEffectiveColumns(LayoutRect(105, 105, 90, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(2u, span.end());
+
+  // Rect intersects (1,1) and (1,2). Dirtied rows also cover the first row.
+  // Dirtied columns also cover the first column.
+  span = section->dirtiedRows(LayoutRect(105, 105, 190, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(2u, span.end());
+  span = section->dirtiedEffectiveColumns(LayoutRect(105, 105, 190, 90));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(3u, span.end());
+
+  // Rect intersects (1,2) and (2,2). Dirtied rows and dirtied columns cover all
+  // rows and columns.
+  span = section->dirtiedRows(LayoutRect(205, 105, 90, 190));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(3u, span.end());
+  span = section->dirtiedEffectiveColumns(LayoutRect(205, 105, 90, 190));
+  EXPECT_EQ(0u, span.start());
+  EXPECT_EQ(3u, span.end());
+}
+
 }  // anonymous namespace
 
 }  // namespace blink